drm/amd/display: fix dc_lock leak on GPU reset error paths

drm/amd/display: fix dc_lock leak on GPU reset error paths

On GPU reset, dm_suspend() takes dc_lock and leaves it for dm_resume()
to drop. If amdgpu_dm_commit_zero_streams() or dm_dmub_hw_init() fails,
the function returns with the lock still held. The matching resume path
is then skipped, so every later dc_lock take hangs.

Release the cached DC state and unlock before returning the error.

Fixes: 3cf7a0bc87f0 ("drm/amd/display: Catch failures for amdgpu_dm_commit_zero_streams()")
Fixes: 2b6943df5413 ("drm/amd/display: Pass up errors for reset GPU that fails to init HW")
Cc: stable@vger.kernel.org
Signed-off-by: Linkai Gong <gonglinkai@kylinos.cn>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>